This should get the job done:
data=[-7.55;-7.62;-7.59;-7.75;-7.78;-7.69;-7.63;-7.69;-7.58;-7.95];
newdata=interp1(...
1:numel(data),... create x values
data,... treat the data as y values
1:0.5:numel(data),... create the new x values to sample
'linear'); % force the use of a linear interpolation
disp(newdata)
